What would be considered safer (overall) - ritalin (methylphenidate) or adderall?

ADD med safety: Ritalin (methylphenidate) and Adderall (dextroamphetamine and racemic amphetamine) (dexamphetamine) have comparable safety profiles, however Adderall (dextroamphetamine and racemic amphetamine) may have slightly more risk of side effects (appetite, sleep, anxiety). In the absence of underlying heart problems, or family hx of early cardiac deaths there should be no heart issues, but if used your doctor should check your blood pressure and heart rate periodically.

No difference: There is no significant difference between the two medications in terms of safety.